Die for cutting taper threads.



No. 763,816- I PATENTED JUNE 28, 1904.

W. VOSPER. I

DIE FOR CUTTING TAPER THREADS.

' APPLICATION FILED DBO. 9. 1901.

N0 MODEL.

WITNESSES:

UNITED STATES I Patented June 28, 1904.

PATENT OEEIcE.

WILLIAM VOSPER, OF SANDUSKY, OHIO, ASSIGNOR TO THE TOLEDO PIPE THREADINGMACHINE OHIO.

(30., OF TOLEDO, OHIO, A CORPORATION OF DIE' FOR CUTTING TAPE'R THREADS.

SPECIFICATION forming part of Letters Patent No. 763,816, dated June 28,1904. Application filed December 9, 1901. Serial ITO-85,193- (No model.)

To all whom it may concern.-

Be it known that I, WILLIAMVVOSPER, a citizen of the United States,residing at Sandusky, in the county of Erie and State of Ohio, haveinvented a new and useful Die for Cutting Taper Threads on the Ends ofMetal Tubes or Bars, of which the following is a specification.

My invention relates to improvements in dies for threading wroughtironpipe and other metal tubes; and the objects of my improvement are,first, to provide chasers or cutters that can be more easily suppliedwith oil or other lubricant While cutting, also giving the chips moreroom to escape, so they will not interfere in the backing off of thedie; second, to reduce the power required for cutting a taper thread;third, to dispense with the burs which are left across the threads wherethe cutting edges of other dies for cutting tapers stop cutting. Iattain these objects by means of the devices and arrangement of partshereinafter described, and shown and illustrated in theaccompanyingdrawings, in which Figure 1 is an end elevation of mydevice, and Fig. 2 a central longitudinal sectional elevation of thesame.

Like letters of reference indicate like parts in both views.

In the drawings, D is the die-carrying head, upon the outer face ofwhich are supported a series of dies or chasers A, which slide radiallyendwise and freely in the guides a projeeting beyond the face of thedie-carrying head, and held within said guides by the clamping orholding plates O. The work-holder F is internally threaded at f toengage the external screw-threads d on the sleeve cl, formed integralwith the die-carrying head D, and is provided with one or moreset-screws G, by means of which the object or work to be threaded isclamped immovably in the workholder.

The work-holder F is provided with a flange above the ring or collar Eto prevent relative longitudinal movement between the workholder andring or collar E, but permitting relative rotation of such parts.

Rigidly secured to the ring or collar E are the pins B B, which projectthrough suitable holes in the head D adjacent the rear ends of thechasers A, said holes coinciding with the paths of the chasers A as theymove endwise. The pins B B have a taper b at one side, which taperedportion engages the rear ends of the chasers while the straight side 6moves against the Wall of the hole in the head D, and preferably therear ends of the chasers are beveled to engage the bevel of the pins.

It will be noted that two of the opposite guides (0 project radiallyfrom the head D to provide recesses a with which engage the handles d,by which the die-head is turned.

The operation of my device is as follows: The work to be threaded isinserted through the openings in the work-holder and the internal sleeved until it comes in contact with the inner side of the chasers A, whichare ground with suitable lead. The clampingscrews are now tightened andthe head carrying the cutters is revolved upon the object to be threadedby means of the handles, causing the parts D and the work-holder bymeans of their screw-threaded engagement to approach each other. Thering E and the pins B revolve with the head. As the work proceeds theinclined faces of the pins permit the chasers to recede radially, thusgradually increasing the diameter of the thread and forming ataperedthread which conforms to the taper of the pins B.

The chasers A are set out from the outer face of the head D, as shown,to allow the lubricant to be readily applied and to allow the cuttingsto fall clear of the work. The face of the chasers being much narrowerthan the length of the thread and the first two or three teeth of thechasers doing the cutting, there will be no bur left, as in the case ofordinary dies, where all of the teeth cut at once and alike.

Having described my invention and its operation, What I claim, anddesire to secure by Letters Patent, is

1. The combination of a Work-support having a threaded interior With acollar rotatably mounted thereon, tapering pins projecting from saidcollar, a die-head having a tubular threaded projection adapted toengage the screw-threads of the Work-holder, and chasers having theirrear ends arranged to engage the inner faces of the tapering pins.

2. The combination of a Work support, means for securing the object tobe threaded to said Work-support, a series of tapering pins, rotatablemeans upon said Work-support carrying said pins, a die-head rotatablyand longitudinally movable upon the Work-support, and chasers mountedupon the die-head and engaging the tapering pins.

3. In a die for cutting tapered threads, a Work-support, means forsecuring the worksupport to the object to be threaded, a collarrotatably mounted upon the Work-support and carrying a series oftapering pins, a die-head rotatably and longitudinally mounted upon thework support, holes in said die head through Which the tapering pinsproject, and chasers mounted upon the die-head and having their rearends in engagement With the tapering pins.

In testimony whereofI have signed my name to this specification inthepresence of two subscribing Witnesses.

\VILLIAM VOSPER. Witnesses W. L. FIESINGER, E. S. STEPHENS.

